NOTE: At the time of this posting, there was no NVIDIA Web Driver release for the 2017 iMac 5K's Sierra 10.12.5 build (16F2073). When released, we will try connecting the GTX 1070 and other NVIDIA Pascal GPUs to the 2017 iMac 5K using a Thunderbolt 3 eGPU box.

LuxMark 3 OpenCL - The default option is to render the LuxBall scene using all available GPUs. You can override the default by pausing once the rendering starts. Change settings. Then restart rendering.(HIGHER KSamples per Second = FASTER)

Heaven OpenGL Benchmark - Heaven Benchmark is a GPU-intensive benchmark that hammers graphics cards to the limits. You fly through a magical steampunk world of shiny brass, wood and gears. It leverages the most advanced capabilities of OpenGL 4.0.(HIGHER frames per second = FASTER)

Tomb Raider OpenGL game - We ran the built-in Benchmark using High Quality preset at 2560x1440 fullscreen.(HIGHER frames per second = FASTER)

Motion - Using the 600 frame Atmospheric - OPEN template, we timed how long it took to render the RAM Preview. (Because the iMac 5K test unit only had 8GB of RAM, it only rendered 294 of the 600 frames, thereby skewing the results to make it look faster. We converted the result to frames per second to give a more accurate picture of its performance.)(HIGHER frames per second = FASTER)

WHAT DID WE LEARN?The Radeon Pro 580 in the 2017 iMac 5K is clearly faster than the previous iMac 5K's optional R9 M395X GPU.

With the exception of the Motion RAM Preview, the Pro 580 was slower than the GeForce GTX 1070 we were running in the Mac Pro tower. That's not surprising since the 1070 is rated at 6.5 teraflops and the Pro 580 is rated at 5.5 teraflops.

Once we add more memory to the iMac 5K, we will run some serious pro app benchmarks. We will include the 2017 iMac 5K quad-core i7 with 1TB PCIe based flash storage which should arrive in a few more days.